Solar-powered chip, battery not required

Pete Danko EARTHTECHLING, 13th January 2011

Solar-powered microelectronics? Not unusual. But a solar-powered microchip with no battery - that is to say, a chip with the solar cell integrated into it and running directly off available light - now that's a breakthrough.

And it's one being claimed by researchers from the University of Twente's MESA+ Institute for Nanotechnology, working with colleagues from Nankai University in China and and Utrecht University in the Netherlands.

As you might expect for something that had never been done, accomplishing this battery-less photovoltaic-powered microchip was touchy business.

The researchers wanted to use the chip as a base and apply the solar cell to it layer by layer - but doing so risked damaging the chip's electronics.

According to the University of Twente, they overcame this hurdle by using solar cells made of amorphous silicon or CIGS (copper-indium-gallium-selenide), which had the happy result of not messing up the electronics.

The researchers suggest that without a battery, "a sensor chip can be produced, complete with the necessary intelligence and even an antenna for wireless communication."

The chip can even collect enough solar power to operate indoors, although its energy use, they note, "must be well below 1 milliwatt."

The researcher's paper, "above-CMOS a-Si and CIGS Solar Cells for Powering Autonomous Microsystems" - highlighted recently on Gizmag.com - was delivered in December at International Electron Device Meeting in San Francisco.